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Archived Epidemiology Publications // -2010

Shaw, S, Blanchard JF, Bernstein CN. Association between the use of antibiotics in the first year of life and pediatric inflammatory bowel disease. American Journal of Gastroenterology 2010; 105: 2687-2692.

The development of commensal flora in infants has been shown to be sensitive to antibiotic use.  Altered intestinal flora is thought to contribute to the etiology of IBD, an idiopathic chronic condition.  We aimed to determine if early use of antibiotics was associated with development of IBD in childhood. We accessed the population-based University of Manitoba Inflammatory Bowel Disease Epidemiologic Database. IBD status was determined from a validated administrative database definition.  A total of 36 subjects diagnosed between 1996 and 2008 were matched to 360 controls, based on age, sex and geographic region. Antibiotic data were drawn from the Manitoba Drug Program Information Network, a comprehensive population-based database of all prescription drugs for all Manitobans dating back to 1995.  Antibiotic use in the first year of life was compared for IBD cases versus controls. The mean age at IBD diagnosis was 8.4 years. Twenty one cases (58%) had one or more antibiotic dispensations in their first year of life, versus 39% of controls.  Crohn’s disease was diagnosed in 75% of IBD cases. Those receiving one or more dispensations of antibiotics were 3 times more likely of being an IBD case than a control.  We concluded that subjects diagnosed with IBD in childhood are more likely to have used antibiotics in their first year of life.


Nugent Z, Blanchard JF, Bernstein CN. A population based study of health care resource use among infliximab users. American Journal of Gastroenterology 2010; 105: 2009-2016.

There has been some evidence from clinical trials that persons who received infliximab (Remicade) or adalimumab (Humira) would be less likely to require hospitalization or surgery over the course of 1 year follow up than persons who got placebo within the course of the clinical trial. Hence we wanted to study the “real world” experience of hospitalization surgery and doctor visits among infliximab users compared with those who didn’t use infliximab. As comparison groups to infliximab users we included a group of patients who were prescribed azathioprine (Immuran), or 6-mercaptopurine (Purinthol) for the first time, a group who were prescribed at least 30 days of steroids (prednisone) and a group who were prescribed none of prednisone, azathioprine, 6-mercaptopurne, methotrexate, or infliximab. IBD-associated doctor visits were consistently higher for infliximab users; both pre- and post- initial dosing, although overall physician visits were similar between those who used infliximab, those who used azathioprine or 6-mercaptopurine, and those who had a new course of steroids. There was a steep rise in hospitalizations in the 6 months prior to initial prescription of infliximab, azathioprine (or 6-mercapotopurine) or steroids and hospitalizations were higher in the infliximab group until 18-24 months after the first prescription at which point levels fell to those evident 2-5 years prior to initiating infliximab and to levels in the other drug groups. The likelihood of surgery post dosing was greater in the infliximab users than in the group using azathioprine (or 6-mercapotopurine) or the group using none of these immune drugs for up to 36 months but the surgery rate was not different than the group newly prescribed steroids.

We concluded that in a “step-up” approach to infliximab use (where only more ill patient get prescribed this medication) it takes 2 years for doctor visits to reduce to 2 year pre dosing rates and 18-24 months to reach hospitalization rates at 2 years pre dosing and hospitalization rates of other groups using azathioprine (or 6-mercapotopurine) or steroids. Surgical rates to 3 years post dosing were still higher than in other groups using azathioprine (or 6-mercapotopurine) or steroids.

One argument for expending the high cost of infliximab is that it could reduce or even eliminate the high cost of hospitalization or surgery. We could not show that infliximab use decreased health care utilization to levels below pre-infliximab therapy or levels below the other Crohn’s disease patient groups. Considering the high expense of infliximab it may be difficult to prove cost effectiveness in a “step-up” approach to initiating the drug where it is reserved for the most ill patients unless indirect costs (the costs of missing work or school) and quality of life are accounted for.


Bernstein CN, Nugent Z, Longobardi T, Blanchard JF. Isotretinoin is not associated with inflammatory bowel disease: A population based case control study. American Journal of Gastroenterology 2009; 104: 2774-2778.

There has been some discussion in the medical literature whether persons using isotretinoin (Accutane or its generic forms)  to treat acne are at increased risk of getting IBD. In this study we assessed the use of isotretinoin prior to diagnosis of IBD and in comparison with a matched control group who did not get IBD. We found that 1.2% of IBD cases used isotretinoin prior to IBD diagnosis which was statistically similar to controls (1.1% users). This was also similar to the number of IBD patients who used isotretinoin after a diagnosis of IBD was made (1.1%). There was no difference between isotretinoin use prior to Crohn’s disease compared with use prior to ulcerative colitis. We concluded that patients with IBD were no more likely to have used isotretinoin prior to diagnosis than controls matched by sex, age and area of residence. While there may be anecdotes of isotretinoin causing acute colitis our data suggest that isotretinoin is not likely to cause chronic IBD.


Shanahan F, Bernstein CN. The evolving epidemiology of inflammatory bowel disease. Current Opinion in Gastroenterology 2009; 25:301-305.

Bernstein CN, Shanahan F. Disorders of a modern lifestyle– reconciling the epidemiology of inflammatory bowel diseases. Gut 2008; 57:1185-1191.

These reports update current trends in the epidemiology of IBD including the emergence of IBD in developing countries. The emergence in developing nations may provide important clues to the causes of IBD.


Bernstein CN (on behalf of organizing committee). Assessing environmental risk factors affecting the inflammatory bowel diseases: A joint workshop of the Crohn’s & Colitis Foundations of Canada and the USA. Inflammatory Bowel Diseases 2008; 14: 1139-1146.

This was a report of a meeting sponsored by the CCFC and CCFA bringing together experts on studying the environment in IB D and other diseases.


Tang L, Nabalamba A, Graff LA. Bernstein CN. A comparison of self-perceived health status in IBD and IBS from a Canadian national population survey. Canadian Journal of Gastroenterology 2008; 22: 475-483.

In this study we used data from the 2005 Canadian Community Health Survey which had a sample size of 132,947 Canadians to determine whether differences exist in perceptions of physical health, mental health and stress levels between patients with IBD and patients with irritable bowel syndrome (IBS). Information on 4441 participants aged 19 years or older who reported that they had been diagnosed with Crohn’s disease (n=474), ulcerative colitis (n=637) or IBS (n=3330) was analyzed. We found that people with IBD were more likely to experience fair or poor general health. IBS patients reported higher levels of stress and poorer mental health than IBD patients.


Longobardi T, Bernstein CN. Utilization of health-care resources by patients with IBD in Manitoba: a profile of time since diagnosis. American Journal of Gastroenterology 2007; 102(8): 1683-1691.

Administrative databases were used to report resource use in 2000/1. We found that within the first 2 years from disease diagnosis, the most costly resources were employed. Independent of disease duration, in general, outpatient utilization was over twice as likely among IBD cases compared with controls whether or not the contact was made for IBD-specific reasons. The likelihood of health care utilization was greatest among newly diagnosed cases for outpatient visits with an internist (an increase by 6-fold over non-IBD controls) and surgical visits (an increase by 3-fold over non-IBD controls). Inpatient stays for IBD-specific reasons in general were considered dependent on disease duration; in particular, there was a 4-fold higher likelihood for the incident (new) cases relative to their controls. For non-IBD-specific reasons, IBD cases were 1.5 times as likely to have inpatient stays, regardless of disease duration. We concluded that we can likely measure the greatest proportion of treatment effects on resource use within a relatively short period. Hence, even if some therapies are very expensive it is possible that their use could limit other expenses that would be incurred otherwise.


Longobardi T, Bernstein CN. Health care resource utilization in IBD. Clinical Gastroenterology and Hepatology 2006; 4: 731-743.

Our Centre is fortunate to have one of the few health economists in the world devoted to studying the economics of IBD. Dr. Teresa Longobardi has been exploring how often persons with Crohn’s disease and ulcerative colitis visit their physicians, get hospitalized or undergo surgery. We found that persons with either Crohn’s disease or ulcerative colitis do have more outpatient visits and more hospitalizations than persons without IBD. Persons with Crohn’s disease have more outpatient visits and more hospitalizations than persons with ulcerative colitis. However, persons with ulcerative colitis are more likely to undergo surgery than persons with Crohn’s disease. Of persons with newly diagnosed Crohns’ disease and ulcerative colitis, over 15 years, there is a 50% chance of being hospitalized and 30% chance of undergoing surgery. In this newly diagnosed group followed over 15 years persons with Crohn’s disease were 4x more likely to be hospitalized and more likely to have surgery than persons with ulcerative colitis.


Bernstein CN, Wajda A, Svenson LW, MacKenzie A, Koehoorn M, Jackson M, Fedorak R, Israel D, Blanchard JF. The epidemiology of inflammatory bowel disease in Canada: a population-based study. American Journal of Gastroenterology 2006; 101: 1559-1568.

In our initial report the incidence rate of Crohn’s disease of 15/100,000 and the prevalence rate of nearly 200/100,000 were the highest yet to be reported in the world. Manitoba got branded as the Crohn’s disease hotspot in the world. In 2004 with funding from the Crohn’s and Colitis Foundation of Canada ($200000) we established collaboration with researchers in BC, Alberta, Saskatchewan, and Nova Scotia. Using the administrative definition for a diagnosis of IBD, applied to the provincial health databases of these other provinces, we estimated that the incidence rate of Crohn’s disease was 13.5/100,000 in 1998-2000 and the prevalence in 2000 of both Crohn’s disease and ulcerative colitis was 155000. We further estimated that in 2005 there would be approximately 170,000 Canadians with IBD. This study also found that rates in Manitoba were similar in Alberta and Saskatchewan, and rates in Nova Scotia were slightly higher than those of the Prairie Provinces. Hence Manitoba was not the Crohn’s disease hotspot but rather Canada was a hotspot. Rates in BC, particularly of Crohn’s disease were significantly lower. This raises the possibility that there is something environmentally different about BC than elsewhere in the country, or that the large immigrant population of BC (with a lower likelihood of having IBD) contributed to lowering the incidence rates of IBD.

Publications // from the Manitoba IBD Epidemiology Database